This protocol is a study to determine if the expression and function of the multidrug resistance drug efflux pump, MDRI P-glycoprotein, can be measured in vivo using technetium-99m-sestamibi imaging. To date, the only method to evaluate mdr-1 expression has required invasive biopsies. We hope this study will demonstrate whether 99mTc-sestamibi can be used as a non-invasive imaging test to determine expression of the mdr-1 gene in vivo. The benefit of monitoring the expression of the mdr-1 gene will be to monitor the accumulation of chemotherapeutic agents that are substrates of the P-glycoprotein efflux pump with a non-invasive technique in vivo. Additionally, it will identify patients that would obtain a greater accumulation of chemotherapy in their tumor if a reversal agent for the P- glycoprotein is given. To date, one person has been placed on the study. The goal is to study 30 patients. The study has begun enrollment only a few months ago because of problems in gaining funding for the cyclosporin A.